Timer for a gas stove

ABSTRACT

A timer for a gas stove has a housing to be mounted to a front panel of the gas stove. A controlling unit, a driving unit and a clutch unit are received in the housing. A switch is provided for ignition of gas and controlling of flames. The controlling unit can be set to a preferred period so that when the period has elapsed, the driving unit is activated to rotate the switch and shut off the gas stove automatically via the clutch unit. In addition, if the switch is turned by the user to ignite the gas or control the flames, the clutch unit is in a disengaged state so that unnecessary wear among components of the timer is prevented.

BACKGROUND OF THE INVENTIONS

[0001] 1. Field of the Invention

[0002] The present invention relates to a timer for a gas stove, and more particularly to a timer which can be easily assembled onto a gas stove by a user, Moreover the timer is designed to have a clutch function in order to prevent unnecessary wear among components thereof.

[0003] 2. Description of Related Art

[0004] A gas stove is a commonly seen appliance placed in a kitchen for cooking. In the early days, the gas stove is only designed to have switches for igniting and controlling flames. Certain kinds of food require long cooking times, and therefore a person may want to leave the kitchen temporarily to attend to other matters. However, on these occasions, it is very likely for the person to forget the cooking of the food and so fail to come back in time. Consequently, the food may be burnt or even cause a serious fire in the kitchen.

[0005] In order to overcome the foregoing problem, a gas stove equipped with a timer has been invented and is currently available in the market. However, the timer is fitted during assembly of the gas stove by factory workers. Hence, a gas stove purchased that is not equipped with a timer cannot then be retrofitted with a timer by the purchaser. The only solution is to purchase a new gas stove designed to have a timing function and this is considered to be costly and wasteful.

[0006] Accordingly, the present invention intends to provide a timer for a gas stove to overcome the aforementioned problems.

SUMMARY OF THE INVENTION

[0007] An objective of the present invention is to provide a timer for a gas stove so that a user can set the timer to automatically shut the gas stove off after a preferred period.

[0008] Another objective of the present invention is to provide a timer for a gas stove which can be easily assembled onto the gas stove by a user in a do-it-yourself way.

[0009] Still another objective of the present invention is to provide a timer for a gas stove which is designed to have a clutch function to avoid excessive wear of the components of the timer.

[0010] Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is an exploded, perspective view of a timer for a gas stove in accordance with the present invention;

[0012]FIG. 2 is a schematic, plane view showing an interior of the timer;

[0013]FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2 showing a clutch unit of the timer in a disengaged state;

[0014]FIG. 4 is a plane view showing the gas stove and the timer mounted thereon; and

[0015]FIG. 5 is a cross-sectional view showing a clutch unit of the timer in an engaged state and also the operation of the timer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0016] With reference to FIG. 1, a timer for a gas stove in accordance with the present invention includes a housing (10), a switch (20), a controlling unit (30), a driving unit (40) and a clutch unit (50).

[0017] The housing (10) has a sleeve (11) received therein and pivotally connected to a front surface thereof. A gear portion (111) is formed at one end of the sleeve (11). A case (12) is mounted at a side of the housing (10) and has an opening defined in the front surface of the housing (10) for receiving a battery (not shown) into the case (12) via the opening. A cover (13) detachably covers the opening. A rear panel (14) further detachably covers a rear opening of the housing (10).

[0018] The switch (20) has a shaft (21) extending therefrom to be received and coupled to the sleeve (11). The shaft (21) further extends to be coupled to an ignition device and a valve of the gas stove for starting and controlling flames.

[0019] The controlling unit (30) is an electronic device having time controlling circuits, controlling buttons (31) and a display (33). The electricity required for operating the controlling unit (30) is supplied by the battery, In addition, the controlling unit (30) is capable of detecting the condition of the battery so that when its voltage is low, an alarm is automatically sounded to alert a user.

[0020] The driving unit (40) is received inside the housing (10) and mounted on the rear panel (14). A motor (41) and a transmission (42) coupled to the motor (41) are included in the driving unit (40), wherein the transmission (42) can be a set of secondary gears as shown in the figures and the activation of the motor (41) is controlled by the controlling unit (40).

[0021] The clutch unit (50) is coupled between the gear portion (111) of the sleeve (11) and the secondary gears of the transmission (42). The clutch unit (50) has an axle (54) securely mounted on the rear panel (14). A barrel (53) having a threaded outer surface (531) is mounted around the axle (54). An annular groove (532) is defined around an end of the barrel (53). A hair spring (533) is mounted on the rear panel (14) while a portion of the hair spring (533) is received in the annular groove (532), and moreover, the portion abuts to the surface defining the annular groove (532) so as to secure the barrel (53) with respect to the axle (54). The clutch unit (50) also has a first gear (51) and a second gear (52). A first toothed surface (511) and a first toothed face (512) are formed on the first gear (51). A threaded bore (513) is centrally defined through the first gear (51) such that the first gear (51) is screwed onto the axle (54) by mating of the threaded bore (513) and the threaded outer surface (531). A through hole (523) is centrally defined in the second gear (52) such that the second gear (52) is rotatably mounted around a free end of the axle (54) by inserting the axle (54) into the through hole (523). A second toothed surface (521) configured to mate the gear portion (111) of the sleeve (11) is formed on the second gear (52). A second toothed face (522) configured to mate first toothed face (512) is also formed on the second gear (52). A spring (55) is mounted around the axle (54) and compressed between the first gear (51) and the second gear (52).

[0022] With reference to FIG. 4, the timer is securely mounted on a front panel of the gas stove and the shaft (21) of the switch (20) is coupled to the ignition and the valve of the gas stove such that by turning the switch (20), the flames can be started and the intensity of the flames can be also controlled. With reference to FIGS. 2 and 3, due to that the first gear (51) and the second gear (52) of the clutch unit (50) are separated, during the turning of the switch (20) for controlling the flame, the driving unit (40) is not driven correspondingly so as to prevent unnecessary wear among components.

[0023] With reference to FIGS. 1, 2 and 5, after gas is ignited, the user can set the controlling buttons (31) to a preferred period, and the related data is shown on the display (33). Once the period has elapsed, the controlling unit (30) activates the motor (41) to rotate the first gear (51) via the transmission (42). Due to the unscrewing of the first gear (51) on the threaded outer surface (531) of the barrel (53), the first gear (51) approaches the second gear (52) to mesh the first toothed face (512) with the second toothed face (522). Thereby, the motor (41) is able to further drive the switch (20) to shut off the gas stove. Finally, the controlling unit (30) rotates reversely to disengage the first gear (51) and the second gear (52).

[0024] It is noted from the above description, the timer for the gas stove in accordance with the present invention has the following advantages:

[0025] 1. The timer is suitable for various kinds of gas stoves and the user can assemble the timer onto the gas stove in a do-it-yourself way. Therefore, the user does not have to purchase an entire gas stove to replace an old gas stove without a timer.

[0026] 2. The clutch unit (30) is at a disengaged state during the rotation of the switch (20) by the user. Therefore, the unnecessary wear among the components is prevented to prolong the life of the timer.

[0027] While this invention has been particularly shown and described with references to the preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims. 

What is claimed is:
 1. A timer for a gas stove having an ignition device and a valve for starting and controlling flames, the timer comprising: a housing to be mounted on the gas stove and to receive a battery, a sleeve pivotally connected to the housing and adapted to be coupled to the ignition device and the valve; a switch having a shaft extending therefrom, the shaft further extending into and coupled to the sleeve so that a user is able to turn the switch for starting and controlling the flames; a controlling unit to be supplied power by the battery, and having an electronic circuit to provide a timing function and multiple controlling buttons to set the controlling unit; a driving unit mounted inside the housing and having a motor and a transmission coupled to the motor; and a clutch unit having an axle extending from an inner surface of the housing, a barrel securely mounted around the axle and having a threaded outer surface formed thereon, the clutch unit also having a first gear and a second gear, the first gear coupled with the transmission and screwed on the barrel by mating a threaded bore defined through the first gear and the threaded outer surface of the barrel, a first toothed face formed on the first gear, the second gear coupled with the sleeve and mounted around the axle, a second toothed face formed on the second gear to mesh with the first toothed face, a spring mounted around the axle and compressed between the first gear and the second gear, whereby a user is able to set the controlling unit to a preferred period so that once the period has elapsed, the controlling unit automatically activates the motor and thereby rotates the shaft to shut the gas stove off.
 2. The timer as claimed in claim 1, wherein the controlling unit further comprises a display mounted on the housing.
 3. The timer as claimed in claim 1 wherein the sleeve has a gear portion formed thereon, and a toothed surface is formed on the second gear and meshed with the gear portion so as to couple the sleeve with the second gear.
 4. The timer as claimed in claim 1, wherein the barrel has an annular groove defined therearound, and a hair spring is mounted on the inner surface of the housing, a portion of the hair spring received in the annular groove and abutted to a surface defining the annular groove so as to secure the barrel with respect to the axle.
 5. The timer as claimed in claim 15 wherein the transmission comprises a set of secondary gears.
 6. The timer as claimed in claim 1, wherein the housing further has a case mounted therein, and an opening is defined in the housing and communicates with a hollow interior of the case so that the batteries is able to be fitted into the case via the opening.
 7. The timer as claimed in claim 6 further comprising a cover detachably covering the opening. 